Concrete wall systems and methods and spacers therefor

ABSTRACT

A concrete wall system includes first and second opposing wall panels and a plurality of spacers disposed between the first and second wall panels. A plurality of reinforcing bars is placed between the first and second wall panels and supported by the spacers, and a concrete core is disposed between the first and second wall panels such that the spacers and the reinforcing bars are embedded in the concrete core. Each one of the spacers has a cup-like body defining a closed first end and an open second end with a flange formed on the second end. The spacer bodies are tapered so that the spacers are stackable.

BACKGROUND OF THE INVENTION

This invention relates generally to concrete wall systems, methods formaking concrete wall systems, and spacers used in concrete wall systems.

Many structures and buildings are made with concrete walls.Traditionally, this type of construction involves setting up forms,pouring concrete between the forms, and then removing the forms afterthe concrete hardens. It is also common to utilize reinforcing bars(commonly referred to as “rebar”) in the concrete.

Australian Patent Application No. 2000101212 discloses another type ofconcrete wall that comprises an opposing pair of formwork boards and aplurality of wall spacers located between the formwork boards.Reinforcing bars are placed through respective openings formed in thespacers, and the cavity between the formwork boards is then filled withconcrete. The formwork boards remain in place, acting as the finishedinternal or external wall surface.

The concept disclosed by Australian Patent Application No. 2000101212has several drawbacks. For instance, the spacers are box-shaped and thusoccupy a considerable volume when packed for shipping, thereby resultingin relatively high shipping cost. Australian Patent Application No.2000101212 also does not disclose techniques for efficiently assemblingthe formwork boards and spacers. Nor does Australian Patent ApplicationNo. 2000101212 teach how to build high structures or columns orefficiently incorporate electrical conduits and the like within thepre-filled wall prior to pouring concrete.

SUMMARY OF THE INVENTION

The above-mentioned need is met by the present invention, which providesa concrete wall system comprising first and second opposing wall panelsand a plurality of spacers disposed between the first and second wallpanels. A plurality of reinforcing bars is placed between the first andsecond wall panels and supported by the spacers, and a concrete core isdisposed between the first and second wall panels such that the spacersand the reinforcing bars are embedded in the concrete core. Each one ofthe spacers has a cup-like body defining a closed first end and an opensecond end with a flange formed on the second end. The spacer bodies aretapered so that the spacers are stackable.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of a spacer forpositioning two opposing wall panels relative to one another.

FIG. 2 is a cross-sectional view of the spacer taken along line 2-2 ofFIG. 1

FIG. 3 is a perspective view (in partial cut-away) of a concrete wallsystem.

FIG. 4 is a cross-sectional view of a portion of the concrete wallsystem of FIG. 3.

FIG. 5 is a perspective view of a portion of a building constructed withconcrete wall systems.

FIG. 6 is a perspective view of an integrated concrete column.

FIG. 7 is a diagram depicting a process for making shell assemblies forconcrete wall systems.

DETAILED DESCRIPTION OF THE INVENTION

The present invention includes integrated concrete wall systems thatcomprise two opposing wall panels separated by a plurality of spacersand a concrete core located between the two wall panels. The spacersposition the two wall panels relative to one another. Specifically, thespacers maintain the two wall panels parallel to one another and spacedapart a particular distance to insure that the resulting wall system hasa uniform and desired thickness. The spacers are also adapted to supportreinforcing bars, as well as other items such as electrical conduit, inplace between the wall panels before the concrete is poured into theinter-panel space.

Referring to the drawings wherein identical reference numerals denotethe same elements throughout the various views, FIGS. 1 and 2 show oneembodiment of a spacer 10 for use in a concrete wall system. The spacer10 comprises a cup-like body 12 having a closed end 14, an open end 16and an interior that defines a hollow cavity. The body 12 is shown inthe drawings as having a box-shaped configuration by way of example, butit should be noted that other shapes (such as a circular cross-section)are possible. In the illustrated embodiment, the body 12 comprises fourside walls 18 joined together in mutually orthogonal fashion to definefour corners. Each side wall 18 is joined to a rectangular base piece 20at the closed end 14 of the body 12. The body 12 includes a rectangularflange 22 formed along the perimeter thereof at the open end 16. Therectangular flange 22 extends outward from each of the four side walls18 and is substantially parallel to the base piece 20.

The exterior or outwardly-facing surface of the base piece 20 can beattached to the one of the wall panels, and the outwardly-facing surfaceof the flange 22 can be attached to the other wall panel. These surfacescan be attached via any suitable means, such as adhesive or the like.Because the flange 22 and the base piece 20 are substantially parallel,an attached spacer 10 functions to maintain the opposing wall panels inparallel relation and at the desired spacing (which is determined by thelength of the spacer 10).

The body 12 includes an opening 24 formed in each one of the four sidewalls 18 for receiving reinforcing bars (vertical and horizontal) aswell as other items such as electrical conduit. As described in moredetail below, a number of spacers 10 are deployed to hold thereinforcing bars in the proper positions during construction of aconcrete wall system.

The body 12 is tapered with the four side walls 18 converging slightlyso that the cross-sectional area of the closed end 14 is smaller thanthe cross-sectional area of the open end 16. The tapered configurationand hollow cavity of the body 12 make the spacer 10 stackable; that is,multiple spacers 10 can be stacked together. This stackable spacerconfiguration greatly reduces packing and shipping costs as largevolumes of the spacers can be packed and shipped in a minimum of space.

The spacers 10 can be made as a one-piece construction, such as with aninjection molding process. Injection molding is highly automated, andthe spacers 10 can be molded and stacked as they are produced, whichfurther lowers packing costs. The spacers 10 can be made of any suitablematerial, including plastic. Plastic materials are generally lightweightand will not corrode when set in concrete.

Referring to FIGS. 3 and 4, one embodiment of a concrete wall system 30is shown. The concrete wall system 30 shows a first wall panel 32 and anopposing second panel wall 34 (shown partially cut-away in FIG. 3)arranged in parallel, spaced-apart relation so as to define aninter-panel space 36 therebetween. The bottom portion of each wall panel32, 34 abuts a corresponding side of a channel 38 that is attached tothe floor and is typically made of metal. The wall panels 32, 34 aresecured to the channel 38 by any suitable fastener 40. While the panels32, 34 could be placed inside the channel 38, they are preferablypositioned externally of the channel 38, as depicted in the drawings, soas to present a continuous surface finish.

A plurality of spacers 10 is disposed in the inter-panel space 36between the first and second wall panels 32, 34. The base piece 20 ofeach spacer 10 is attached to the first wall panel 32, and the flange 22of each spacer 10 is attached to the second wall panel 34 in anysuitable manner. For example, the base pieces 20 and the flanges 22 canbe attached to the respective wall panels using a fast-drying urethaneglue. In the illustrated embodiment, the spacers 10 are arranged in agrid-like layout of vertical columns and horizontal rows. The number andspacing of the spacers 10 will depend on the structural design. Forexample, about forty spacers 10 would typically be equidistantly spacedon a four-foot by ten-foot panel as would be used for most home orcommercial construction. This assemblage of the first and second wallpanels 32, 34 and the spacers 10, referred to hereinafter as the shellassembly, is typically made at a factory and then transported to theconstruction site. At the construction site, the shell assembly is slipfit over its floor channel 38 and the wall panels 32, 34 are fastenedthereto as described above. Reinforcing bars are then interlaced withthe spacers 10. Specifically, a vertically-extending reinforcing bar 42is placed to extend through the openings 24 formed in thehorizontally-oriented side walls 18 of each column of spacers 10, and ahorizontally-extending reinforcing bar 44 is placed to extend throughthe openings 24 formed in the vertically-oriented side walls 18 of eachrow of spacers 10.

Once the wall panels 32, 34, channel 38, spacers 10 and reinforcing bars42, 44 are assembled as shown in FIG. 3, the concrete wall system 30 iscompleted by pouring concrete into the inter-panel space 36 of the shellassembly. The concrete cures and forms a concrete core 46 (shown in FIG.4) that provides structural integrity to the concrete wall system 30.The spacers 10 and the reinforcing bars 42, 44 are embedded in theconcrete core 46. The two wall panels 32, 34 remain and function as theinner and outer wall surfaces of the concrete wall system 30.

Referring to FIG. 5, a portion of a building constructed with theconcrete wall systems is depicted. Specifically, FIG. 5 shows a cornerof a building formed by two concrete wall systems 30A, 30B arrangedperpendicularly to one another. Each concrete wall system 30A, 30Bincludes a floor channel (not shown in FIG. 5), and a shell assemblycomprising a first or inner wall panel 32 and a second or outer wallpanel 34 arranged in parallel, spaced-apart relation with the inner wallpanel 32 so as to define the inter-panel space 36 therebetween. The wallpanels 32, 34 can be made from any suitable materials approved by thestructural engineer and meeting applicable fire and building codes. Forexample, the inner wall panels 32 could comprise any wood (e.g., plywoodor other composition board material), composite material or the likehaving adequate strength for attaching the spacers 10 and retaining thepoured concrete.

The outer wall panels 34 could comprise a board of an insulatingmaterial (such as polyurethane (PU) closed-cell foam or expandedpolystyrene (EPS)) having an outer finish surface of wood, metal orplastic clad thereto. Pre-finished outer wall panels 34 with aninsulating foam board would provide thermal insulation for the building,thereby eliminating the need for a separate layer of insulation andconsequently saving labor costs and speeding up overall constructiontime. Any number of exterior sidings, including horizontal or verticalmetal clad sidings, can be applied to the outer surface of theinsulating foam board using pressure sensitive adhesives. For example,foam panels can be purchased pre-finished with vacuum bag appliedexterior sidings such as aluminum and steel. To quickly applyfinish-lapping strips to joints (not shown), tape adhesives can be usedand can withstand temperatures to 200 F. Concrete adheres well to PUfoam, which has an R-value of 6.5 per inch compared to an R-value of 4per inch for EPS foam.

As an alternative to insulated outer wall panels, the concrete wallsystems 30A, 30B could be provided with a third wall panel (not shown)arranged in parallel, spaced-apart relation outside of the outer wallpanels 34 (which would thus become intermediate wall panels). The spacesbetween these sets of panels would be filled with insulating material.

Each concrete wall system 30A, 30B further includes a plurality ofspacers disposed in the inter-panel space 36 between the wall panels 32,34. One of the wall systems 30A uses the tapered, cup-like spacers 10shown in FIGS. 1 and 2. The other wall system 30B uses a plurality ofalternative spacers 48. The alternative spacers 48 can be custom madefrom a length of PVC pipe 50 having a thin end cap 52 secured to eachend thereof. The outer surfaces of the end caps 52 present surfaces thatcan be attached to the respective wall panel 32, 34 by any suitablemeans, such as adhesive or the like. The PVC pipe 50 is provided withseveral openings 54 spaced around the circumference thereof so as to bealigned in pairs for receiving reinforcing bars (vertical andhorizontal) as well as other items such as electrical conduit. Thealternative spacers 48 can be custom cut to length and generally wouldbe used for thicker walls and columns.

The construction further includes a corner assembly 56, described inmore detail below, which connects the two perpendicular concrete wallsystems 30A, 30B and completes the building corner. Prior to installingthe corner assembly 56, the vertical and horizontal reinforcing bars 42,44 are interlaced with the spacers 10/48. In addition, electricalconduit 58 can be installed by insertion through the openings 24/54 ofselected spacers 10/48. In the illustrated embodiment, additionalspacers 10/48 are located between columns and rows of spacers 10/48 thathold vertical and horizontal reinforcing bars 42, 44 in order to supportelectrical conduit 58 at a desired height or heights. Preferably, eachsuch additional spacer is centered between a two adjacent columns ofreinforcing bar-holding spacers and between two adjacent rows ofreinforcing bar-holding spacers.

Openings for doors and windows can be zip cut in the shell assemblies atthe factory where they are made or on site, with pre-assembled roughopening spacers (not shown) inserted and fastened in place to the wallpanels prior to pouring concrete. The corner assembly 56 comprises twocorner pieces 60 joined together at a 90 degree angle and two pre-gluedstrips 62 that are used to attach the corner pieces 60 to thecorresponding outer wall panels 34 once the reinforcing bars 42, 44 andconduit 58 are all installed. Generally, the corner pieces 60 and thepre-glued strips 62 would be used with fiber cement panels, which arechamfered on the outer edges to apply finishing tape for application ofother finish coatings. If the outer wall panels 34 have insulating foamthickness pre-applied inside, a slot would be cut in the foam adjacentto the inside surface of each wall panel to accommodate the pre-gluedstrips 62. Any number of combinations of wall panels 32, 34 can be usedproviding they are engineer approved for the particular constructionsystem.

Reinforcing bars, conduit, junction boxes and all interior plumbing areinstalled prior to the pour of concrete into inter-panel space 36. Oncethe wall panel assemblies are all in place with reinforcing bars securedand connected and all conduit is secured and connectors glued, junctionboxes 64 can be installed. Because junction boxes are located at anengineered height from the floor, the conduit 58 is placed at thisheight. Junction box panel openings can thus be rotary zip cut into theinner wall panel 32 anywhere along the conduit length, and the conduit58 is cut to produce a gap equal to the exact outside width of thejunction box 64 and aligned with the junction box panel opening. Glue isapplied to the fittings 66 formed in the sides of the junction box 64,and the junction box 64 is then inserted into the opening in the innerwall panel 32 and the gap in the conduit 58 such that tabs 68 on thejunction box abut the inner wall panel 32. Thus, as many junction boxesas needed can be quickly and efficiently located anywhere along thelength of the conduit with a tight and secure fit made to the junctionbox 64, the conduit 58 and the inner wall panel 32 before pouringconcrete. Conduit that does not have a well-defined location can havejunction boxes and fittings pre-installed as wall panels are set, which,with location rough-marked on the inner wall panel 32 and/or with a ironwasher (not shown) taped to the inside a plastic junction box, can alsobe quickly and exactly located later with a magnet to rotary zip cut thejunction box opening into the inner wall panel 32. Channels (not shownin FIG. 5) for positioning inner and outer wall panels would be securedto poured concrete floors, with the slip fit of panels over thepre-installed channel and fastened though the outside of the panel tothe channel to hold in the concrete from the pour. All panel walls arebuttressed as needed before filing with concrete to maintain the desiredposition. Straight, angled, curved, or irregular wall panelconfigurations are possible. The wall panels can also be tilted orpositioned at an angle, such as for decoration or special architecturaleffect.

Turning to FIG. 6, one embodiment of a column 70 made with theprinciples of the present invention is shown. The column 70 is aspecialized concrete wall system that comprises four panels 72-75arranged in mutually orthogonal fashion to form a rectangularconfiguration. The first and third panels 72, 74 are arranged parallelto each other, and the second and fourth panels 73, 75 are arrangedparallel to each other. Adjacent panels 72-75 are joined together withpre-glued corner pieces 76 that are set in place and the whole assemblyis banded together (not shown) for glue drying so as to maintain theintegrity and dimensions of the assembly prior to filling with concrete.Two spacers 48 (of the alternate type described above) extendhorizontally between the first and third panels 72, 74. Each spacer 48comprises a length of PVC pipe 50 having a thin end cap 52 secured toeach end thereof. Horizontal reinforcing bars 44 are inserted lengthwisein the PVC pipe 50 prior to securing the end caps 52. The outer surfaceof each end cap 52 is attached to the respective panel 72, 74 by anysuitable means, such as adhesive or the like.

Vertical reinforcing bars 42 are inserted through openings 54 in the PVCpipe 50 and tied to the horizontal reinforcing bars 44. The openings 54are larger than the reinforcing bars 42 in order to receive thereinforcing bars 42 and still have clearance to allow the PVC pipe 50 tofill with concrete. The amount and size of the vertical and horizontalreinforcing bars 42, 44 depends on the size of the column 70 with asmany horizontal layers of reinforcing bars 44 as needed to meet code.Each layer of spacers 48 and horizontal reinforcing bars 44 would beshifted 90 degrees with respect to its adjacent layers. In other words,the layer of spacers 48 and horizontal reinforcing bars 44 locateddirectly below the layer shown in FIG. 6 would be rotated 90 degrees sothat the spacers 48 extend between, and are attached to, the second andfourth panels 73, 75.

Once the panels 72-75, spacers 48 and reinforcing bars 42, 44 areassembled, concrete is poured into the assembly. The concrete fills theinterior of the assembly and also flows into the spacers 48 via theopenings 54. The concrete cures and forms a concrete core that providesstructural integrity to the column 70.

FIG. 7 is a diagram depicting how shell assemblies for concrete wallsystems can be economically assembled at a factory or the like forfuture field assembly of concrete wall systems at a construction site.The first step is to shear the panels to size at a station 80. Thepanels are conveyed to the next station 82 via rollers 84 locatedbetween stations 80 and 82. Although not shown, there are similarrollers located between all of the subsequent stations. If fiber cementpanels are used, the next station 82 provides a radial saw for cuttingand removing a small amount of panel material at the edges thereof, toaccommodate adding tape and joint compound for finishing wall jointsflat on the exposed sides of the panels. The next station 86 provides atemplate positioned onto a panel to facilitate placing spacers. Glue isthen applied at the next station 88 and panels sandwiched together asneeded. As previously noted, there could be two panels joined togetheror as many as three panels making two spaces, one for concrete and onefor insulation. The assembled panels are then conveyed to the nextstation 90 to be clamped and compressed until the glue sets. Afterremoving from the clamp assembly, the assembled panels can be furtherprocessed by installing window and door rough opening inserts and thendelivered to the job site for final assembly prior to pouring concrete.

For supporting concrete wall systems in multi-story structures, wallsystem thickness at the ground floor will start at a relative thickvalue, say twelve inches thick. The wall system thickness will begradually reduced for higher and higher floors, such as to ten inches,then to eight inches, then to six inches, then to four inches thick perthe structural engineer's design for a twenty-four story building, forexample, to create an earthquake and fire proof building of highquality. To accomplish this, stackable spacers could be mass produced atthe various widths and panel assemblies fit over and secured to thestandard width channels that are attached to the concrete floors at eachstory to accommodate securing and lining up panels for pouring concrete.Alternatively, PVC fabricated spacers could also be produced asnecessary for thicker starting walls. And regardless of climate, asnoted previously, either PU or EPS insulated foam board outer panel canbe used, or a second outside insulating space can be created with athird panel and filled with approved insulating materials to construct astrong, airtight structure enabling good air quality control and beingwell insulated. Everything combines to make highly energy efficient,quality buildings.

While specific embodiments of the present invention have been described,it should be noted that various modifications thereto can be madewithout departing from the spirit and scope of the invention as definedin the appended claims.

1. A spacer for positioning two opposing wall panels relative to one another, said spacer comprising: a cup-like body defining a first end and an open second end and having a base piece at said first end and a flange formed on said second end; wherein said base piece presents a surface that is attachable to a first one of said two wall panels and said flange presents a surface that is attachable to a second one of said two wall panels; and wherein said body is tapered such that said first end has a smaller cross-sectional area than said second end.
 2. The spacer of claim 1 wherein said body comprises four side walls arranged in mutually orthogonal fashion, said base piece is rectangular in shape and is connected to said four side walls at said first end of said body, and said flange is rectangular in shape and extends outward from each of said four side walls.
 3. The spacer of claim 2 further comprising at least one opening formed in each one of said four side walls.
 4. The spacer of claim 1 wherein said spacer is of a single-piece construction.
 5. The spacer of claim 1 wherein said spacer is made of injection molded plastic.
 6. A concrete wall system comprising: first and second opposing wall panels; a plurality of spacers disposed between said first and second wall panels, each one of said spacers comprising a cup-like body defining a first end and an open second end and having a base piece at said first end and a flange formed on said second end, said body being tapered such that said first end has a smaller cross-sectional area than said second end; wherein each base piece is attached to said first wall panel and each flange is attached to said second wall panel; a plurality of reinforcing bars placed between said first and second wall panels and supported by said spacers; and a concrete core disposed between said first and second wall panels such that said spacers and said reinforcing bars are embedded in said concrete core.
 7. The concrete wall system of claim 6 wherein each cup-like body comprises four side walls arranged in mutually orthogonal fashion, said base piece is rectangular in shape and is connected to said four side walls at said first end of said body, and said flange is rectangular in shape and extends outward from each of said four side walls.
 8. The concrete wall system of claim 7 wherein each cup-like body has at least one opening formed in each one of said four side walls, and wherein said reinforcing bars extend through corresponding openings.
 9. The concrete wall system of claim 6 wherein each base piece is attached to said first wall panel with an adhesive and each flange is attached to said second wall panel with an adhesive.
 10. The concrete wall system of claim 6 further comprising a channel attached to a floor, and wherein a bottom portion of said first wall panel abuts and is fastened to one side of said channel and a bottom portion of said second wall panel abuts and is fastened to another side of said channel.
 11. The concrete wall system of claim 6 wherein one of said first and second wall panels comprises a board of insulating material with an outer finish surface clad thereto.
 12. A method of constructing a concrete wall system comprising: providing a shell assembly comprising first and second opposing wall panels in parallel, spaced-apart relation so as to define an inter-panel space therebetween with a plurality of spacers disposed in said inter-panel space, each one of said spacers comprising a cup-like body defining a first end and an open second end and having a base piece at said first end and a flange formed on said second end, said body being tapered such that said first end has a smaller cross-sectional area than said second end; inserting reinforcing bars through openings formed in said spacers; and pouring concrete into said inter-panel space.
 13. The method of claim 12 further comprising: attaching a channel to a floor; fitting said shell assembly over said channel with a bottom portion of said first wall panel abutting a first side of said channel and a bottom portion of said second wall panel abutting a second side of said channel; and fastening said first wall panel to said first side of said channel and said second wall panel to said second side of said channel prior to pouring concrete into said inter-panel space.
 14. The method of claim 12 further comprising inserting at least one electrical conduit through openings formed in said spacers prior to pouring concrete into said inter-panel space.
 15. The method of claim 14 further comprising installing a junction box in said shell assembly prior to pouring concrete into said inter-panel space.
 16. The method of claim 15 wherein installing a junction box includes: cutting an opening in said first wall panel; cutting a gap is said conduit, wherein said gap is aligned with said opening in said first wall panel; and inserting said junction box into said opening in said first wall panel and said gap such that tabs on said junction box abut said first wall panel.
 17. A column comprising: first, second, third and fourth panels arranged in mutually orthogonal fashion to form a rectangular configuration, wherein said first and third panels are arranged parallel to each other and said second and fourth panels are arranged parallel to each other; at least one spacer extending between said first and third panels, said spacer comprising a length of pipe having an end cap attached to each and multiple openings formed therein; a horizontal reinforcing bar inserted lengthwise in said length of pipe; at least one vertical reinforcing bar inserted through a pair of said openings formed in said length of pipe; and a concrete core disposed between said first, second, third and fourth panels such that said spacer and said reinforcing bars are embedded in said concrete core.
 18. The column of claim 17 wherein said length of pipe is PVC pipe.
 19. The column of claim 17 further comprising a second vertical reinforcing bar inserted through a second pair of said openings formed in said length of pipe.
 20. The column of claim 17 further comprising: a second spacer extending between said first and third panels, said second spacer comprising a second length of pipe having an end cap attached to each and multiple openings formed therein; a second horizontal reinforcing bar inserted lengthwise in second said length of pipe; and a second vertical reinforcing bar inserted through a pair of said openings formed in said second length of pipe.
 21. The column of claim 17 further comprising: a second spacer extending between said second and fourth panels, said second spacer comprising a second length of pipe having an end cap attached to each and multiple openings formed therein; and a second horizontal reinforcing bar inserted lengthwise in second said length of pipe.
 22. The column of claim 21 wherein said at least one vertical reinforcing bar is inserted through a pair of said openings formed in said second length of pipe.
 23. The column of claim 21 further comprising a second vertical reinforcing bar inserted through a pair of said openings formed in said second length of pipe. 